In recent years, a multi-core system is used in a personal computer and so on where each memory is shared among a plurality of cores. The multi-core system makes it possible to simplify the control of memory access when one process is performed by two or more cores cooperatively. Further, since each memory can be accessed from a plurality of cores, memory resources can be used efficiently.
In the multi-core system, there is a likelihood that when a useless data transfer is performed between the core and the memory, another data transfer is obstructed and the performance of the entire system is deteriorated.